Conventionally, for example, Patent Document 1 discloses a valve operating apparatus for an internal combustion engine including a configuration in which an electric motor rotationally drives a drive camshaft to which a driven cam lobe which drives a valve is fixed. Further, the conventional valve operating apparatus includes a motor control device which controls the rotational speed of the electric motor. According to the configuration like this, the rotational speed of the electric motor is changed by the motor control device, and thereby the rotational speed of the driven cam lobe for an interval in which the drive camshaft makes one rotation can be increased and decreased.
The applicant recognizes the documents described as follows including the above described document, as the documents relating to the present invention.